AD 57-06-03

57-06-03 PRATT & WHITNEY: Applies to All Wasp Major Engines.

Compliance required as soon as possible but not later than May 31, 1957.

As a result of propeller shaft oil transfer bearing failures, several cases of loss of propeller control occurred which make it impossible to feather the affected propellers. It has been determined that brazing of the propeller shaft oil transfer tube adapter to the propeller shaft oil transfer bearing is subject to failure if the brazing is not adequate.

To assure that the brazed joint is satisfactory, the following inspection must be accomplished on bearings with brazed oil tube transfer adapters:

1. X-ray the brazed joints to determine if brazing is satisfactory (limits established by Pan American World Airways and/or Pratt & Whitney Aircraft.)

2. Subject the bearing to 1,500 p.s.i. hydraulic pressure test.

3. Conduct a dye penetrant inspection of the brazed joints.

If the bearing does not pass these inspectionsit must be repaired or replaced.

A new bearing, P/N 341627, which has eliminated the brazed joints is available and may be used. This new bearing does not require the above mandatory inspections. Information on inspection procedure and limitation is available from Pratt & Whitney Aircraft.